Note: Descriptions are shown in the official language in which they were submitted.
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ADJUSTABLE 11~IONTTORING GUIDE
. This applicati~Iaims~ariu 'gym Provisional Patent Application Serial No.
BACKGROUND
IO
1. Field 'of the Invention
This invention relates to roller guides of the type employed in rolling mills
to
.guide rod and bar products into roll passes..
. 2. Description of the Prior Art
in ,the rolling of steel rods and bars, significant operational benefits can
be
realized by_ ~ ploying so-called "reducing-sizing mills" ("RSM") of the type
disclosed
in U.S~. ~'~tteat~o~ 5,325,697 '- ,
. Advantages of rolling with
such mills include improved ~ dimensional control of the finished product,
higher mill
. utilization and increased free sizing capability. ~ . .
. Figure 1 illustrates; a typical pass progression of the reducing-sizing
process,
. which begins with a leading oval 10 followed by three round passes, 12, 14
and 16.
Relatively small changes in the finished round bar or rod can be made by
changing the
. 25 roll partings on the last three round passes. Alternatively, the feed
section, which is
,typically round, can be changed slightly, but this entails adjusting upstream
aiili
equipment; resulting in a non round feed section, which can impose other
process
limitations.
There has been a relucance on the pan of those skilled in the art to undertake
any parting changes to the oval pass 10, owing to problems associated 'with
adjusting
downstream roller entry guides to exactly match the resulting modified oval.
Previous
technology roller guides ~ do not have the capabiIiry to be precisely adjusted
whilst
located on the mill and an off line alignment station is usually used for
this, which
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2
obviously requires removal of the guide from the mill and therefore a mill
stoppage.
Feeding an oversized section through a roller entry guide is not desirable
since this
drastically reduces the life of the bearings within the guide rollers and can
lead to some further
processing problems. If the oval section is adjusted to be smaller than the
guide setting, a severe
oscillation of the rolled product manifests within the guide, causing severe
processing problems
and poor quality finished product.
An objective of the present invention is to provide a roller guide assembly
which can be
precisely adjusted on line to accommodate different sized process sections,
thus making it
possible for example to change the parting of the oval pass 10, which in turn
beneficially
increases the free sizing capability of the mill.
US-A-4790164 describes a roller guide assembly for guiding roller material
between the
passes of roll stands. The known assembly has a pair of guide rollers
rotatably supported on
parallel axes at opposite sides of the rolled material. A local sensor serves
to ascertain the
pressure exerted on the rollers by the rolled material and provides a signal
used to adjust the
guide rollers.
According to the invention there is provided a roller guide assembly for
guiding a
workpiece into a roll pass of a rolling mill, said guide assembly comprising:
a rigid housing structure;
a pair of roller holders emending lengthwise of the housing structure on
opposite sides of
the intended direction of travel of the workpiece;
CA 02368752 2001-09-25
FOR THE PURPOSES OF INFORMATION ONLY
Codes used to identify States party to the PCT on the front pages of pamphlets
publishing international applications under the PCT.
AL Albania ES Spain LS Lesotho SI Slovenia
AM Armenia FI Finland LT Lithuania SK Slovakia
AT Austria FR France LU Luxembourg SN Senegal
AU Australia GA Gabon LV Latvia SZ Swaziland
AZ Azerbaijan GB United KingdomMC Monaco TD Chad
BA Bosnia and GE Georgia MD Republic TG Togo
Herzegovina of Moldova
BB Barbados GH Ghana MG Madagascar TJ Tajikistan
BE Belgium GN Guinea MK The former TM Turkmenistan
Yugoslav
BF Burkina Faso GR Greece Republic TR Turkey
of Macedonia
BG Bulgaria HU Hungary ML Mali TT Trinidad
and Tobago
BJ Benin IE Ireland MN Mongolia UA Ukraine
BR Brazil IL Israel MR Mauritania UG Uganda
BY Belarus IS Iceland MW Malawi US United States
of America
CA Canada IT Italy MX Mexico UZ Uzbekistan
CF Central AfricanJP Japan NE Niger VN Viet Nam
Republic
CG Congo KE Kenya NL Netherlands YU Yugoslavia
CH Switzerland KG Kyrgyzstan NO Norway ZW Zimbabwe
CI Cdte d'IvoireKP Democratic NZ New Zealand
People's
CM Cameroon Republic PL Poland
of Korea
CN China KR Republic PT Portugal
of Korea
CU Cuba KZ Kazakstan RO Romania
CZ Czech RepublicLC Saint Lucia RU Russian Federation
DE Germany LI LiechtensteinSD Sudan
DK Denmark LK Sri Lanka SE Sweden
EE Estonia LR Liberia SG Singapore
30-04-2001 - US 00001202 ~
2a
pivot means for mounting said roller holders on said housing structure for
pivotal
movement about parallel first axes, said pivot means being positioned between
forward and
rearward sections of said roller holders;
guide rollers carried on the forward sections of said roller holders for
rotation about
second axed parallel to said first axes, said guide rollers defining a gap
therebetween and being
configured to engage and guide the workpiece into the roll pass of the rolling
mill;
adjustment means acting on the rearward sections of said roller holders for
pivoting said
roller holders in opposite directions about said first axes to thereby adjust
the size of said gap;
force exerting means for exerting yieldable forces urging the forward sections
of said
roller holders apart while urging the rearward sections of said roller holders
into contact with said
adjustment means, the magnitude of said yieldable forces varying in a
generally linear
relationship with respect to changes in the size of the gap defined by said
guide rollers; and
force sensing means associated with said adjustment means for generating
output signals
representative of the magnitude of said yieldable forces.
Further preferred features of the invention are defined in the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a diagrammatic illustration of a typical pass progression in a
reducing-sizing
process;
Figure 2 is a partially sectioned top plan view of a roller guide assembly in
accordance
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30-04-2001 CA 02368752 2001-09-25 US 00001202
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2b
with the present invention;
Figure 3 is a partially sectioned side view of the roller guide assembly;
Figure 4 is a partially sectioned side view of the roller guide assembly as
viewed from
right to left in Figure 3;
Figure Sa diagrammatically illustrates the forces acting on one of the guide
arms; and
Figure Sb is a graph depicting the relationship between the measured force
acting on each
roller holder and its deflection from an initial reference setting.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIZVVIENT
Referring initially to Figures 2-4, a roller guide assembly in accordance with
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WO 00/66288 PCT/US00/12027
3
the present invention is generally indicated at 18. The guide assembly
includes a rigid
housing structure commonly referred to as a "guide box" having a base 20, with
integral laterally spaced side members 22, and a nose piece 24. A pair of
roller
holders 26 extends lengthwise of the housing structure on opposite sides of
the intended
direction of travel "T" of the workpiece, in this case an oval process section
received
from the oval pass 10 for delivery into the next successive round pass 12.
Guide rollers 28 are rotatably carried at the forward ends of the roller
holders
26. The guide rollers define a gap therebetween, and are configured to engage
and
guide the oval process section so that it is correctly presented to the round
pass, with
the elongate axis "A" of the oval (shown in Figure 1 ) normal to the axes of
the rolls of
the round pass 12.
The housing structure further includes vertical pivots 30 on which the roller
holders 26 are mounted for movement about axes extending generally parallel to
the
rotational axes of the guide rollers 28.
Compression springs 32 are located in bores in the roller holders 26. The
springs abut the side members 22 of the housing structure and are captured in
their
respective bores by cover plates 34 secured to the roller holders. The springs
32 are
loaded in compression and as such, exert yieldable forces "F" (see Figure Sa)
on the
roller holders urging the roller holders to rotate in opposite directions
about the pivots
30, as depicted diagrammatically by the arrows in Figure 2.
The spring-induced rotation of the roller holders is resisted by stops
comprising
adjusting screws 36 positioned to be contacted by load sensitive sensors 38
carried on
rearward extensions of the roller holders.
As can be seen in Figure 4, the adjusting screws 36 are threaded into right
and
left hand threaded sections of the side members 22 of the housing structure.
The
square ends 42 of the adjusting screws slide axially within the square bore 40
of a gear
44 meshing with a gear 46 on a drive shaft 48 having two drive points 48a,
48b. The
drive point 48a is for manual adjustment, generally used for off line setting
of the
guide. The other point 48b mates with the output shaft SO of a 90° gear
box 52
powered either manually, or by a motor (not shown) which may be controlled
remotely.
As shown in Figure Sa, the force F exerted by the spring 32 is opposed by
force
"L" , with the sensors 38 serving to measure the magnitude of the force F.
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4
Various modes of operation are possible after initial set-up.
1. Position Control Mode
Figure Sb shows that when the guide is adjusted to its desired setting "G,",
the
output of each sensor is recorded as "F, " . The guide is then deflected to a
different
known setting "G," by means of gauge bar or other means of controlled
deflection (not
shown), and the new sensor output "FZ" recorded. This can be repeated for
several
other setting if desired for improved accuracy. However, two points are
usually
sufficient to describe the relationship between guide setting and sensor
output which is
generally linear.
Knowing the relationship between guide setting and sensor output enables the
guide to be adjusted to a pre-determined sensor setting "FX" which corresponds
to the
desired parting between the guide roller "GX" . Hence the guide can be
accurately
positioned without being removed from the mill.
When changes are required to the process oval, the guide can be remotely
adjusted in order to re-position the guide rollers to the desired oval height,
leading to
an increase in the free sizing range capability of the reducing and sizing
operation.
2. Sensor Output Control Mode
For this mode it is assumed that the spring element used within the guide has
negligible variation when the guide parting is adjusted by small amounts.
The guide is set as detailed above and once the rollers are at the correct
setting
for the section being rolled, the output of the sensor (or sensors) is
recorded.
The guide is then installed on the mill and when the stock enters the guide,
the
sensor output is again monitored and recorded. If the mill is set correctly,
the sensor
output during rolling should be very close to that of the initial setup. If
not, then the
mill roll gap can be adjusted to change the height of the leading oval until
this
condition is met.
When adjustments are required to the oval pass, the guide can be adjusted
using
the remotely operable adjustment apparatus as detailed above, such that the
parting
between the guide rollers is approximately the magnitude required by the new
set up.
When the first bar of the new size enters the guide, the sensor output is
monitored and
compared with the initial setup value. If necessary the guide can be adjusted
accordingly until the correct output is achieved. Ideally this is undertaken
in automatic
closed loop control, but may also be controlled manually.
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WO 00/66288 PCT/US00/12027
This mode of operation ensures that the guides are always set to match the
dimensions of the process oval. When the process oval is changed, the guide
can be
made to adapt accordingly, therefore leading to an increase in the free sizing
range
capability of the reducing and sizing operation.
5 This mode also enable the guide to be set to eliminate over-loading or
oscillating stock as well as enabling the guide to be remotely adjusted in
accordance
with temperature and yield strength changes associated with different grade
products.
All of the above concepts can be applied to the rolling of shapes and flat
product as well as rounds.
In light of the foregoing, it will now be appreciated by those skilled in the
art
that various changes and modifications nay be made to the embodiment herein
chosen
for purposes of disclosure without departing from the spirit and scope of the
invention
as defined by the appended claims. For example, although compression springs
32
have been disclosed, other force exerting components could be substituted,
including
disc springs, fluid actuated devices, elastomers, etc. The sensors may be
other than
load sensitive, including for example those sensitive to strain, pressure
deflection, etc.
Also, although two sensors are shown, one for each roller holder, an
acceptable
alternative would be to employ only one sensor on one of the roller holders.
I claim:
